Vim (Vi improved) is an extremely powerful editor. This cheatsheet covers only what you need to edit a few git commit messages.
i go to insert mode
v go to visual mode
(cursor keys) navigate
:wq save and quitreset
:q quit, if no unsaved changes
:q! quit anyway
y yank (=copy)
c cut
p paste
u undo
Ctrl+R redo
ESC back to command mode
(usual editing functionality)
ESC back to command mode
(cursor keys) modify selection
y yank (=copy) selection
c cut selection
p paste selection